Alphabetical list of English proverbs ~ this site is nice because it provides an explanation for each proverb. However, they are all English and aren't searchable by subject or theme.
English Proverbs - Phrase finder ~ this site only contains English proverbs as well; however, many of them are clickable and contain footnotes as to what the proverb means and when it first appeared from where in the English language.
Creative Proverbs from 300 countires ~ this site allows you to search by country, or by subject/theme. When you click on the Proverbs Search Engine be sure to read the tips on how to use the search engine and utilize the FRANK option.
ProverbsPlace ~ The largest collection of proverbs I can find. Searchable by country and occasionally by word.
Romantic Literature Proverbs Project
Proverbs Template
Proverbs Example
Proverbs Rubric
Proverbs Websites